Question

我有一个有三个面板的JFrame：

======================================
|                                    |
|                                    |
|          Green Panel               |
|                                    |
|                                    |
|                                    |
======================================
|          Blue Panel                |
|                                    |
======================================
|      Button1       Button2         |
|                                    |
======================================

当我点击Button1时，我想隐藏蓝色面板并禁用Button1。当我点击Button2时，我想显示蓝色面板并禁用Button2。

我知道我可以使用setVisible（boolean）来显示和隐藏组件。

我的问题是，当我隐藏蓝色面板时，如何使绿色面板扩展并占用以前由蓝色面板占用的空间？相反，当我点击Button2时，我希望蓝色面板重新出现，绿色面板又回到之前的尺寸？

如果不对面板的尺寸进行硬编码，可能会出现这种情况，因为我可能想要增加窗口尺寸。

Answer 1

您可以使用JPanel的getHeight（）方法，如下所示

JPanel pnlGreen = new JPanel();
JPanel pnlRed = new JPanel();

if(e.getSource() == btnOne){
   pnlRed.setHeight(pnlRed.getHeight()+pnlGreen.getHeight());
   //Panel and Button show/hide code
}
else if(e.getSource() == btnTwo){
   pnlGreen.setHeight(pnlRed.getHeight()+pnlGreen.getHeight());
   //Panel and Button show/hide code
}

if you want to apply this on window resize then add this code to window minimize and maximize event

Answer 2

此代码使用BorderLayout执行您所需的操作。

它不漂亮但是有效。

public class TESTMAIN extends JFrame {

    private JPanel contentPane;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    TESTMAIN frame = new TESTMAIN();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public TESTMAIN() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(new BorderLayout(0, 0));

        JPanel panel = new JPanel();
        contentPane.add(panel, BorderLayout.CENTER);
        panel.setLayout(new BorderLayout(0, 0));

        JPanel greenPanel = new JPanel();
        greenPanel.setBackground(Color.GREEN);
        panel.add(greenPanel, BorderLayout.CENTER);

        final JPanel bluePanel = new JPanel();
        bluePanel.setBackground(Color.BLUE);
        panel.add(bluePanel, BorderLayout.SOUTH);

        JPanel panel_1 = new JPanel();
        contentPane.add(panel_1, BorderLayout.SOUTH);
        panel_1.setLayout(new BorderLayout(0, 0));

        JButton button1 = new JButton("New button");
        button1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                bluePanel.setVisible(false);
            }
        });
        panel_1.add(button1, BorderLayout.WEST);

        JButton button2 = new JButton("New button");
        button2.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                bluePanel.setVisible(true);
            }
        });
        panel_1.add(button2, BorderLayout.EAST);
    }

}

java按钮点击事件展开面板

2 个答案: